Merge topic '17350-python37-fix' into release

706f1b39 Fix compilation issue due to Python3.7 API change

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: David E. DeMarle <dave.demarle@kitware.com>
Merge-request: !4490

Wrapping/PythonCore/vtkPythonArgs.cxx

@@ -95,13 +95,21 @@ bool vtkPythonGetStringValue(PyObject *o, T *&a, const char *exctext)
 {
   if (PyBytes_Check(o))
   {
+#if PY_VERSION_HEX >= 0x03070000
+    a = const_cast<char *>(PyBytes_AS_STRING(o));
+    return true;
+#else
     a = PyBytes_AS_STRING(o);
     return true;
+#endif
   }
 #ifdef Py_USING_UNICODE
   else if (PyUnicode_Check(o))
   {
-#if PY_VERSION_HEX >= 0x03030000
+#if PY_VERSION_HEX >= 0x03070000
+    a = const_cast<char *>(PyUnicode_AsUTF8(o));
+    return true;
+#elif PY_VERSION_HEX >= 0x03030000
     a = PyUnicode_AsUTF8(o);
     return true;
 #else